Salix Pharmaceuticals will work with California-based Watson Pharma to offer a generic version of the bowel drug Colazal.

Salix, which makes Colazal, said it wants to sell what it calls an “authorized” generic as part of its efforts to increase market share.

Colozal is used to treat mildly to moderately active ulcerative colitis.

“Watson is a major supplier of generic pharmaceutical products, and, with decades of experience and impressive expertise in the generics business, should be positioned to maximize our generic business,” said Carolyn Logan, president and chief executive officer at Salix.